The soft tissue profile has been studied extensively in orthodontics, primarily from lateral cephalometric radiographs, under the assumption that the form of the soft tissue outline largely determines the esthetics of the whole face. The purpose of this study was to assess the relative contribution of the shape of the soft tissue profile outline on the attractiveness of the face, as seen from the profile view. Pretreatment color profile facial photographs of 20 female patients were used. The photographs were scanned, and the soft tissue outlines were digitized. The average outline of the 20 original photographs was then calculated and used as a template for modifying the photographs with computer warping methods. This resulted in 20 warped photographs, all with the same soft tissue outline. Three additional photographs were constructed with 1 face-the composite average of the 20 original photographs-and 3 hairstyles from 3 of the original pictures. The photographs were printed and presented to 10 laypersons and 10 orthodontists for scoring. Scoring was performed on 2 occasions separated by at least 1 week. On the first occasion, the original photographs of 10 of the patients and the warped photographs of the other 10 patients were shown. At the next session, the remaining 10 original and 10 warped photographs were shown. The 3 composite photographs were interspersed with the 20 pictures shown to the judges in each scoring session. Judges were asked to score facial attractiveness on a scale of 0 to 10. The judges were unaware of both the computer modification of the photographs and the purpose of the study. Good agreement was noted between the judges, although the orthodontists tended to be more influenced by the profile outline than did the laypersons. The 3 averaged composite photographs were consistently given the highest scores. The modified photographs were given higher scores than their original counterparts, showing that facial attractiveness is influenced by soft tissue outline form. However, the score improvement was not sufficient to reach the level of the composite images, especially for faces initially judged as being unattractive. This shows that factors other than profile outline shape may be more influential in facial esthetics.

Advances in computer vision have started to infiltrate the specialty of orthodontics. During the past few years, a number of new products have appeared that are capable of extracting the 3-dimensional (3-D) structure of an object just by "looking." Examples include laser scanners for creating 3-D models of the face, and hand-held scanners for creating virtual models of the teeth. Such noninvasive methods will surely evolve rapidly and be applied to a multitude of diagnostic and therapeutic modalities, changing the way we think and practice. This article introduces the basic principles behind such technology so that we can better appreciate its advantages, limitations and possibilities. From the large number of methods for acquiring 3-D shapes from images, 4 were selected and are described below. For more comprehensive coverage, see the book by Klette et al (1).